1999 Volume 64 Issue 523 Pages 63-70
New attenuation relationships for peak ground acceleration on soil ground and for peak ground velocity on stiff ground are developed based on the database of strong motion recordings from 21 Japan earthquakes. In the database, the near-source recordings are included, and the earthquakes are classified into three groups according to the fault type. The new attenuation relationships show that an intra-plate earthquake generates stronger acceleration and velocity than inter-plate and crustal events. The results also show that the earthquake with deeper focal depth generates stronger ground motion.